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m_a_m_a [10]
3 years ago
9

In a collection of nickels, dimes, and quarters worth $6.90, the ratio of the number of nickels to dimes is 3:8. The ratio of th

e number of dimes to quarters is 4:5. Find the number of each type of coin.
Mathematics
1 answer:
dimulka [17.4K]3 years ago
8 0
N=number of nickels
d=number of dimes
q=number of quarters

example
if n:d=3:8
lets say n=3 and d=8
3*8=8*3
so
8n=3d
slightly confusing but go with it, it migh make sense or it might not


n:d=3:8
8n=3d

d:q=4:5
5d=4q

solve for one of them
solve for nickels in first and quarters in second

8n=3d, n=(3/8)d
5d=4q, (4/5)d=q

5n+10d+25q=690
divide by 5 to make it easeir
n+2d+4q=138
sub (3/8)d for n
sub (4/5)d for q
(3/8)d+2d+5(5/4)d=138
(3/8)d+2d+25/4d=138

3/8+2+25/4=
3/8+16/2+50/8=
69/8

(69/8)d=138
times both sides by 8
69d=1104
divide both sides by 69
d=16

16 dimes
sub back

(5/4)d=q
(5/4)16=q
80/4=q
20=q

(3/8)d=n
(3/8)16=n
48/8=n
6=n



6 nickles
16 dimes
20 quarters
yah
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A truck can travel 80 miles in the same time that ot takes a car to travel 90 miles. If the truck’s rate is 5 miles per hour slo
SIZIF [17.4K]
The truck was going 40 miles per hour

The amount of time was 2 hours:
(90-80: 10)(10/2=5)

80 divided by two is 40


The car was going 45 miles per hour


(90-80:10)(10/2=5)

90 divided by two is 45


Hopefully you find this helpful
3 0
3 years ago
Hi can someone help me out with this problem.
elena-s [515]

Answer:

third side = 9

Step-by-step explanation:

Using Pythagoras' identity on the right triangle.

The square on the hypotenuse is equal to the sum of the squares on the other 2 sides.

let the third side be x, then

x² + 40² = 41², that is

x² + 1600 = 1681 ( subtract 1600 from both sides )

x² = 81 ( take the square root of both sides )

x = \sqrt{81} = 9

The third side is 9

3 0
3 years ago
Read 2 more answers
Someone help me with number 2 please
WARRIOR [948]
Dang that’s hard , hope somebody helps you.
4 0
3 years ago
Read 2 more answers
PLEASE HELP- Vanessa earns a base salary of $400.00 every week with an additional 5% commission on everything she sells. Vanessa
matrenka [14]
The commission is 5% on everything she sells
If she sold $1650.00
First you have to find her commission
100%=1650
5%=x
100•x=1650•5
100•x=8250
—— ———
100 100
x=82.5(this is her commission)
Now you have to add $82.5 to total she earns in the week.
$400.00+ $82.5 = $482.5
The Vanessa’s total pay last week was $482.5
7 0
3 years ago
(Past Due) Need Help
Charra [1.4K]

I would say its the second one.

the student shouldve distributed the 2^3x+3 into 2^3x+9

8 0
3 years ago
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